Devices, systems, and methods to fixate tissue within the regions of body, such as the pharyngeal conduit

ABSTRACT

Devices, systems and methods develop static and/or kinetic and/or pressure forces to fixate or brace tissue in targeted pharyngeal structures and individual anatomic components within the pharyngeal conduit.

RELATED APPLICATIONS

This application is a continuation of application Ser. No. 12/148,175,filed Apr. 17, 2008 which was co-pending at the time of filing andsubsequently issued as U.S. Pat. No. 8,752,552; which is a divisional ofapplication Ser. No. 10/718,254 filed Nov. 20, 2003 and issued as U.S.Pat. No. 7,360,542; which is a continuation-in-part of U.S. patentapplication Ser. No. 10/656,861, filed Sep. 6, 2003 entitled “MagneticForce Devices, Systems, and Methods for Resisting Tissue Collapse withinthe Pharyngeal Conduit”, and issued as U.S. Pat. No. 7,188,627; whichclaims the benefit of U.S. Provisional Patent Application Ser. No.60/441,639, filed Jan. 22, 2003 and entitled “Magnetic Splint Device andMethod for the Treatment of Upper Airway Collapse in Obstructive SleepApnea, and the benefit of U.S. Provisional Patent Application Ser. No.60/456,164, filed Mar. 20, 2003 and entitled “Device and Method forTreatment of Sleep Related Breathing Disorders Including Snoring andSleep Apnea”. The application Ser. No. 10/718,254 is also acontinuation-in-part of U.S. patent application Ser. No. 10/236,455,filed Sep. 6, 2002 and entitled “Systems and Methods for Moving and/orRestraining Tissue in the Upper Respiratory System”, and issued as U.S.Pat. No. 7,216,648. Each of the aforementioned applications areincorporated herein by reference.

FIELD OF THE INVENTION

The invention is directed to devices, systems, and methods for thetreatment of sleep disordered breathing including obstructive sleepapnea.

BACKGROUND OF THE INVENTION I. The Characteristics of Sleep Apnea

First described in 1965, sleep apnea is a breathing disordercharacterized by brief interruptions (10 seconds or more) of breathingduring sleep. Sleep apnea is a common but serious, potentiallylife-threatening condition, affecting as many as 18 million Americans.

There are two types of sleep apnea: central and obstructive. Centralsleep apnea, which is relatively rare, occurs when the brain fails tosend the appropriate signal to the breathing muscles to initiaterespirations, e.g., as a result of brain stem injury or damage.Mechanical ventilation is the only treatment available to ensurecontinued breathing.

Obstructive sleep apnea (OSA) is far more common. It is one of theseveral entities that make up the broader group of sleep disorderedbreathing (SDB). This group of disorders ranges from habitual snoring toOSA. Normally, the muscles of the upper part of the throat keep theairway open to permit air flow into the lungs. When the muscles of theupper airway relax and sag, the relaxed tissues may vibrate as air flowspast the tissues during breathing, resulting in snoring. Snoring affectsabout half of men and 25 percent of women—most of whom are age 50 orolder.

In more serious cases, the airway becomes blocked, making breathinglabored and noisy, or even stopping it altogether. In a given night, thenumber of involuntary breathing pauses or “apneic events” can be quitefrequent. These breathing pauses are almost always accompanied bysnoring between apnea episodes, although not everyone who snores hasOSA.

Lack of air intake into the lungs results in lower levels of oxygen andincreased levels of carbon dioxide in the blood. The altered levels ofoxygen and carbon dioxide alert the brain to resume breathing and causearousal. The frequent interruptions of deep, restorative sleep oftenlead to early morning headaches, excessive daytime sleepiness,depression, irritability, and learning and memory difficulties.

The medical community has become aware of the increased incidence ofheart attacks, hypertension and strokes in people with moderate orsevere obstructive sleep apnea. It is estimated that up to 50 percent ofsleep apnea patients have high blood pressure.

Upon an apneic event, the sleeping person is unable to continue normalrespiratory function and the level of oxygen saturation in the blood isreduced. The brain will sense the condition and cause the sleeper tostruggle and gasp for air. Breathing will then resume, often followed bycontinued apneic events. There are potentially damaging effects to theheart and blood vessels due to abrupt compensatory swings in bloodpressure. Upon each event, the sleeping person will be partially arousedfrom sleep, resulting in a greatly reduced quality of sleep andassociated daytime fatigue.

Although some apneic events are normal in all humans, the frequency ofblockages will determine the seriousness of the disease and opportunityfor health damage. When the incidence of blockage is frequent,corrective action should be taken.

II. Sleep and the Anatomy of the Upper Airway

As FIGS. 1A and 1B show, the upper airway consists of a conduit thatbegins at the nasal valve, situated in the tip of the nose, and extendsto the larynx. Although all tissue along this conduit is dynamic andresponsive to the respiratory cycle, only the pharyngeal conduitstructures—the tissues in the region of the airway that starts behindthe nasal cavity and ends in its connections to the supraglotticlarynx—is totally collapsible. The pharyngeal structures and individualanatomic components within this region include the pharyngeal walls; thebase of the tongue; the vallecula; the hyoid bone and its attachments;the soft palate with uvula, the palatine tonsils with associated pillartissue; and the epiglottis.

The cross sectional area of the upper airway varies with the phases ofthe respiratory cycle. At the initiation of inspiration (Phase I), theairway begins to dilate and then to remain relatively constant throughthe remainder of inspiration (Phase II). At the onset of expiration(Phase III) the airway begins to enlarge, reaching maximum diameter andthen diminishing in size so that at the end of expiration (Phase IV), itis at its narrowest, corresponding to the time when the upper airwaydilator muscles are least active, and positive intraluminal pressure islowest. The upper airway, therefore, has the greatest potential forcollapse and closure at end-expiration. Schwab R J, Goldberg A N. UpperAirway Assessment: Radiographic and other Imaging Techniques.Otolaryngol Clin North Am 1998; 31:931-968.

Sleep is characterized by a reduction in upper airway dilator muscleactivity. For the individual with obstructive sleep apnea (OSA) andperhaps the other disorders which comprise much of the group of entitiescalled obstructive sleep-disordered breathing (SDB), it is believed thatthis change in muscle function causes pharyngeal narrowing and collapse.Two possible etiologies for this phenomenon in OSA patients have beentheorized. One is that these individuals reduce the airway dilatormuscle tone more than non-apneics during sleep (the neural theory). Theother is that all individuals experience the same reduction in dilatoractivity in sleep, but that the apneic has a pharynx that isstructurally less stable (the anatomic theory). Both theories may infact be contributors to OSA, but current studies seem to support thatOSA patients have an intrinsically structurally narrowed and morecollapsible pharynx. Isono S. Remmers J, Tanaka A Sho Y, Sato J, NishinoT. Anatomy of Pharynx in Patients with Obstructive Sleep Apnea and inNormal Subjects. J Appl Physiol 1997: 82:1319-1326.

Although anatomic closure is often accentuated at specific sites, suchas the velopharyngeal level [Isono, Ibid], studies of closing pressures[Isono, Ibid] supports dynamic fast MRI imaging that shows narrowing andcollapse usually occurs along the entire length of the pharynx. ShellockF G, Schatz C J, Julien P, Silverman J M, Steinberg F, Foo TKF, Hopp ML, Westbrook P R. Occlusion and Narrowing of the Pharyngeal Airway inObstructive Sleep Apnea: Evaluation by Ultrafast Spoiled GRASS M RImaging. Am J of Roentgenology 1992:158:1019-1024.

III. Prior Treatment Modalities

To date, the only modality that addresses collapse along the entireupper airway is mechanical positive pressure breathing devices, such ascontinuous positive airway pressure (CPAP) machines. All othermodalities, such as various surgical procedures and oral appliances, bytheir nature, address specific sectors of the airway (such as palate,tongue base and hyoid-vallecula levels), but leave portions ofpharyngeal wall untreated. This may account for the considerably highersuccess rate of CPAP over surgery and appliances in controlling OSA.Although CPAP, which in essence acts as an airway splint for therespiratory cycle, is highly successful, it has some very significantshortcomings. It can be cumbersome to wear and travel with, difficult toaccept on a social level, and not tolerated by many (for reasons such asclaustrophobia, facial and nasal mask pressure sores, airwayirritation). These factors have lead to a relatively poor long-termcompliance rate. One study has shown that 65% of patients abandon theirCPAP treatment in 6 months.

The need remains for simple, cost-effective devices, systems, andmethods for reducing or preventing sleep disordered breathing events.

SUMMARY OF THE INVENTION

One aspect of the invention provides devices, systems and methods thatemploy static and/or kinetic force to fixate or brace tissue in targetedpharyngeal structures and individual anatomic components within thepharyngeal conduit, or within other anatomic structures. When used inthe pharyngeal conduit, the devices, systems, and methods can serve toimpede tissue collapse, when imminent, to maintain patency of thepharyngeal conduit. When used elsewhere, the devices, systems, andmethods can serve different purposes, e.g., to assist in closinganatomic pathways.

In one embodiment, the devices, systems, and methods include at leastone implanted structure. The implanted structure is sized and configuredto remodel native tissue conditions within the targeted tissue region,by altering existing morphology and/or motility and/or shape of tissuethat, if not altered, could lead to tissue collapse, particularly duringthe inspiration phase of the respiratory cycle. The implanted structureestablishes tissue conditions that flexibly fixate or brace the tissue,to resist the collapse of tissue along the pharyngeal conduit whenimminent, i.e., during sleep, but without significantly affecting thenative tissue at times when tissue collapse is not imminent. Thefixation or bracing function of the implanted structure can beaccomplished by either static means, or kinetic means, or a combinationthereof.

The targeted pharyngeal structures and individual anatomic componentswithin this region can include, e.g., the pharyngeal walls; the base ofthe tongue; the vallecula; and the soft palate with uvula.

Another aspect of the invention provides devices, systems, and methodsthat brace or fixate tissue in targeted pharyngeal structures and/orindividual anatomic components within the pharyngeal conduit by use of apressure chamber, which is sized and configured to be located outside ofthe pharyngeal conduit and to hold a pressure that is less thanatmospheric pressure. In one embodiment, the pressure chamber is sizedand configured to hold a pressure that is less than a minimum pressurecondition experienced in the pharyngeal conduit during a respirationcycle. The pressure chamber can be sized and configured, e.g., to beworn about a neck.

The devices, systems, and methods can be used to treat airway collapseand increased airway resistance associated with the entire spectrum ofobstructive sleep-disordered breathing. The devices, systems, andmethods can also be used to lend upper airway support in neurologicalassociated dystonic disorders.

Other features and advantages of the invention shall be apparent basedupon the accompanying description, drawings, and claims.

DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 13 are anatomic views of the upper airway in a human,showing certain pharyngeal structures and individual anatomic componentswithin the pharyngeal conduit, FIG. 1A comprising a lateral view andFIG. 13 is a superior view taken generally along line 1B-1B in FIG. 1.

FIG. 2A shows in a diagrammatic way a force system that uses implantedstructures to fixate or brace tissue in targeted pharyngeal structuresand individual anatomic components within the pharyngeal conduit.

FIG. 2B shows in a diagrammatic way a system that uses pressure tofixate or brace tissue along the pharyngeal conduit.

FIGS. 3A to 3C show an implanted static force structure of a type shownin FIG. 2A that includes a material injected into a targeted tissueregion.

FIGS. 4A to 4D show an implanted static force structure of a type shownin FIG. 2A that includes a material injected into an expandablecontainer implanted in a targeted tissue region.

FIGS. 5A and 5B show an implanted static force structure of a type shownin FIG. 2A that is formed from a pre-shaped material, FIG. 5B showingthe structure implanted in the vallecula for purposes of illustration.

FIGS. 6A to 6F show various embodiments of an implanted static forcestructure of a type shown in FIG. 2A that is formed from an array ofindividual, spaced apart implants that move together as a result oftissue compression to resist tissue collapse along the pharyngealconduit.

FIGS. 7A and 7B show an implanted kinetic force structure of a typeshown in FIG. 2A that is formed from a spring-loaded material, FIG. 5Bshowing the structure implanted in the pharyngeal wall for purposes ofillustration.

FIGS. 7C and 7D show an implanted kinetic force structure of a typeshown in FIG. 2A that is formed from an array of individual,spring-loaded structures that are hinged together to resist tissuecollapse along the pharyngeal conduit.

FIGS. 8A(1)-8A(3) and 8B to 8D show an implanted kinetic force structureof a type shown in FIG. 2A that is shaped due to magnetic forces, FIGS.8C and 8D showing the structure implanted in the pharyngeal wall forpurposes of illustration, and FIG. 8D showing the structure juxtaposedwith another magnetic structure implanted in the base of the tongue.

FIGS. 9A and 9B show an implanted kinetic force structure of a typeshown in FIG. 2A that includes a shape-memory material that assumes apredetermined shape in response to an applied activation energy, FIG. 9Ashowing the structure before shape activation, and FIG. 9B showing thestructure after shape activation.

FIGS. 10A to 10D show an implanted kinetic structure of the type shownin FIGS. 9A and 9B implanted, for the purpose of illustration in apharyngeal wall, FIG. 10C showing the structure being shape activated byuse of an external collar, and FIG. 10D showing the structure beingshape activated by use of a wand inserted in the oral cavity.

FIGS. 11A and 11B show an implanted kinetic force structure of a typeshown in FIG. 2A that includes a shape-memory ferromagnetic alloy thatassumes a predetermined shape in response to an applied magnetic field,FIG. 11A showing the structure before shape activation, and FIG. 11Bshowing the structure after shape activation.

FIGS. 12A to 12E show an implanted kinetic force structure of a typeshown in FIG. 2A that includes an array of soft ferromagnetic materialsthat, when magnetized, assumes a predetermined shape.

FIG. 13 shows an implanted static and/or kinetic force structure of atype shown in FIG. 2A that carries a protective material.

FIGS. 14A and 14B show an implanted static and/or kinetic forcestructure of a type shown in FIG. 2A that is fixed to a vertebra.

FIG. 15 show an implanted static and/or kinetic force structure of atype shown in FIG. 2A that carries a tissue in-growth surface.

FIGS. 16A and 16B and FIGS. 17A to 17C show static and/or kinetic forcestructures of a type shown in FIG. 2A implanted in horizontal arrays intargeted pharyngeal structures and individual anatomic components withinthe pharyngeal conduit.

FIGS. 18A to 18C show static and/or kinetic force structures of a typeshown in FIG. 2A implanted in vertical arrays in targeted pharyngealstructures and individual anatomic components within the pharyngealconduit.

FIGS. 19A and 19B show static and/or kinetic force structures of a typeshown in FIG. 2A implanted in mixed vertical and horizontal arrays andin mixed non-horizontal and non-vertical arrays in targeted pharyngealstructures and individual anatomic components within the pharyngealconduit, with fixation to a vertebra.

FIGS. 20A and 20B show an implanted static and/or kinetic forcestructure of a type shown in FIG. 2A that is fixed to a vertebra.

FIG. 21 shows an illustrative embodiment of a system of the type shownin FIG. 2A that includes static and/or kinetic force structuresimplanted in the pharyngeal wall and adjacent anatomic structures suchas the tongue, vallecula, and soft palate.

FIGS. 22A to 22E shows an illustrative embodiment of a system of thetype shown in FIG. 2A that includes static and/or kinetic forcestructures implanted in the tongue and adjacent anatomic structures.

FIGS. 23A and 23B show a pressure chamber system of a type shown in FIG.2B.

FIGS. 24A to 24C show an illustrative surgical procedure for theimplantation of a static and/or kinetic structure of the type shown inFIGS. 14A and 14B and FIGS. 19A and 19B, during which the structure isfixed to a vertebra.

DETAILED DESCRIPTION

Although the disclosure hereof is detailed and exact to enable thoseskilled in the art to practice the invention, the physical embodimentsherein disclosed merely exemplify the invention, which may be embodiedin other specific structure. While the preferred embodiment has beendescribed, the details may be changed without departing from theinvention, which is defined by the claims.

I. Systems to Fixate or Brace Tissue

A. Implanted Force Systems

FIG. 2A shows in a diagrammatic way a force system 10 that, in use,fixates or braces tissue in targeted pharyngeal structures andindividual anatomic components within the pharyngeal conduit using oneor more implanted structures 12. The force system 10 thereby impedestissue collapse, when imminent, to maintain patency of the conduit. Thesystem 10 can be used to treat airway collapse and increased airwayresistance associated with the entire spectrum of obstructivesleep-disordered breathing. The system 10 can also be used to lend upperairway support in neurological associated dystonic disorders.

In one basic form, the force system 10 comprises at least one fixationor bracing structure 12 (shown in FIG. 2A), which is sized andconfigured to be implanted in a targeted tissue region within thepharyngeal conduit. The size and configuration of the implantedstructure 12 are selected to remodel native tissue conditions within thetargeted tissue region, by altering existing morphology and/or motilityand/or shape of tissue that, if not altered, could lead to tissuecollapse, particularly during the respiratory cycle. The implantedstructure 12 establishes tissue conditions that fixate or brace thetissue, to resist collapse along the pharyngeal conduit when imminent,i.e., during sleep, but without significantly stiffening the nativetissue at times when tissue collapse is not imminent.

The targeted pharyngeal structures and individual anatomic componentswithin this region can include the pharyngeal walls; the base of thetongue; the vallecula; the soft palate with uvula; the palatine tonsilswith associated pillar tissue; and the epiglottis. These anatomicregions are shown in FIGS. 1A and 1B. Representative examples ofembodiments of magnetic force systems 10 in certain targeted pharyngealstructures and individual anatomic components within the pharyngealconduit will be described in greater detail later.

The fixation or bracing function of the implanted structure 12 can beaccomplished by static means. The static means conditions the tissue byvirtue of inherent material properties and shape of the structure 12.For example, a given static implanted structure 12 can take the form ofa fluid or slurry that is injected into tissue to form a gel or a solidmatrix having a shape and/or material properties that apply the staticfixation or bracing force to adjacent tissue. A static implantedstructure 12 can also take the form of a pre-shaped metal and/or polymerand fabric and/or textile and/or ceramic structure having inherentmaterial properties and shape that, once implanted, conditions thetissue. In either situation, the static conditioning remodels themorphology and/or motility and/or shape of adjacent tissue.Representative embodiments of force systems 10 comprising implantedstatic structures 12 will be described in greater detail later.

The fixation or bracing function of the implanted structure 12 can alsobe accomplished by kinetic means. The kinetic means exerts dynamicforces that react to kinetic forces within tissue. The reactive dynamicforces can be generated, e.g., by magnetic field forces and/orspring-like mechanical properties and/or elastic mechanical properties.The reactive dynamic forces not only impart a desired shape to theimplant, but also imparting a dynamic resistance to or bias against achange in the shape. In this arrangement, for example, the implantedkinetic structure 12 can comprise a metal and/or plastic and/or fabricand/or textile and/or ceramic material that possesses a desired springconstant or elastic loading to continuously exert a dynamic reactiveforce, e.g., like a mechanical spring. Implanted kinetic structures 12can also be made from a metal and/or plastic and/or fabric and/orceramic material, which selectively assumes a shaped, elastically loadedcondition in response to an activating force, for example, magnetism ortemperature conditions or electrical energy or electromagnetic force.The reactive dynamic forces exerted impart a desired new morphologyand/or motility and/or shape to adjacent tissue, and also resist achange in these conditions. Representative embodiments of force systems10 comprising kinetic implanted structures 12 will be described ingreater detail later.

The fixation or bracing function of the implanted structure 12 impartsimproved comfort, tolerance, and bio-acceptance to the implantedstructure for the patient. The fixation or bracing function is achievedwithout indiscriminate dampening (i.e., stiffening) the spring constantof native tissue in the pharyngeal conduit (which is not desirable). Thefixation or bracing function is achieved due to the controlledapplication of static and/or kinetic forces that push or pull on tissue,without themselves imparting stiffness to the tissue in the pharyngealconduit. The size and configuration of the implanted structures areselected with the ease and bio-comfort of implantation in mind, while atthe same time providing sufficient static and/or kinetic forces toresist tissue collapse when collapse is imminent, taking into accountthe anatomy of the region of implantation and orientation of othercomponents of the system 10. The implanted structures 12 thereby provideconformability, tolerance, and comfort for the patient, withoutsignificantly dampening the spring constant of native tissue.

Prior to implanting a given structure 12, tissue in the targeted tissueregion may be dilated, e.g., by use of a trocar or expandable structure,e.g., a balloon or inflatable structure, to open a tissue space toreceive the structure. During dilation, the tissue space may bedeliberately sized and shaped, so that the resulting implanted structurebest conforms to the size, shape, and physical characteristics to bringabout the desired physiologic response.

B. Pressure Chamber Systems

FIG. 2B shows in a diagrammatic way a pressure chamber system 14 that,in use, fixates or braces tissue in targeted pharyngeal structures andindividual anatomic components within the pharyngeal conduit by alteringthe differential between internal pressure existing within thepharyngeal conduit (P1 in FIG. 2B) and external pressure existingoutside the pharyngeal conduit (P2 in FIG. 2B). More particularly, thepressure chamber system 14 lowers, in a localized region surrounding allor a portion of the pharyngeal conduit, the external pressure to apressure condition (P2) that is less than atmospheric pressure anddesirably less than the minimum expected pharyngeal pressure (P1), whichtypically occurs during the inhalation phase of the respiratory cycle.The pressure chamber system 14 desirably creates in this localizedregion a pressure differential that impedes tissue collapse to maintainpatency of the conduit. The purpose of the pressure chamber system 14 isto desirably nullify the vector sum of the extralumenal forces on theconduit, to make it de-compressive. These forces are created byatmospheric pressure, gravity, contractive forces caused by upper airwaymuscle activity, and inward forces caused by subatmospheric luminalpressure generated during inhalation.

Like the force system 10, the pressure chamber system 14 can be used totreat airway collapse and increased airway resistance associated withthe entire spectrum of obstructive sleep-disordered breathing. Thepressure chamber system 14 can also be used to lend upper airway supportin neurological associated dystonic disorders.

In one basic form, the pressure chamber system 14 comprises at least oneexternal pressure chamber 16 (shown in FIG. 2B), which is sized andconfigured to be worn by an individual, when desired, about a targetedtissue region or regions within the pharyngeal conduit. The targetedpharyngeal structures and individual anatomic components within thisregion can include the pharyngeal walls; the base of the tongue; thevallecula; the soft palate with uvula; the palatine tonsils withassociated pillar tissue; and the epiglottis.

The pressure chamber 16 establishes a localized pressure condition (P2)about the targeted tissue region that is less than atmospheric pressureand desirably less than the minimum-expected pressure condition presentin the pharyngeal conduit (P1). Exposed to a localized pressuredifferential that is more negative than ambient conditions, tissue alongthe pharyngeal conduit resists collapse when collapse is imminent, i.e.,upon inhalation during sleep. The pressure chamber 16 can be removedduring waking hours.

Illustrative embodiments of implanted force systems 10 and externalpressure chamber systems 14 will now be described.

II. Illustrative Implanted Static Structures Useable with the ForceSystem

A. Injected Fluids and/or Slurries

As FIGS. 3A to 3C show, an implanted static structure 12 can include aninjected material 18 comprising one or more biocompatible liquidcomponents, or one or more solid biocompatible components carried in oneor more liquid biocompatible components. The material 18 can be injectedas a liquid or slurry into a targeted tissue region, e.g., by a syringe22 or the like (as FIG. 3B shows), which can comprise, e.g., the tongue,the vallecula, a pharyngeal wall, or the soft palate/uvula. In onearrangement, upon mixing, the components cross-link, polymerize, orotherwise chemically react to create an in situ biocompatible,non-liquid, static mechanical implant structure 12 (as FIG. 3C shows).Implanted static structures 12 formed in situ from injected materials 18are well suited for implantation in targeted pharyngeal structures andother anatomic components within the pharyngeal conduit.

Prior to injection of the material, tissue in the targeted tissue regionmay be dilated (see FIG. 3A), e.g., by use of a trocar or expandablestructure, to open a tissue space TS to receive the in situ-settingfluid or slurry material 18. During dilation, the tissue space TS may bedeliberately sized and shaped, so that the resulting implant material 18injected into it will possess the size, shape, and physicalcharacteristics to bring about the desired physiologic response.

The biocompatible liquid component may comprise, e.g., an Elastin™media. Alternatively, the liquid component may comprise an oil or lowviscosity liquid that is biocompatible to impart the desired newmorphology and/or motility and/or shape to surrounding tissue. The solidcomponent may be a polyvinyl acetate (PVA) or foam that is appropriatelysealed to provide biocompatibility. Other materials such as siliconerubber, elastomeric polymers and polytetrafluoroethylene (Teflon®Material, from DuPont) may also be selected. Alternatively, a powder,small beads, or shavings of solid material can be mixed with a slurry orliquid.

As FIG. 3C shows, the injected liquid or slurry may be formulated to setin situ, to form an implanted static implant 12, possessing the shape,position and mechanical properties to impart the desired new morphologyand/or motility and/or shape to surrounding tissue.

Alternatively (see FIGS. 4A to 4D), the fluid or slurry material 18 maybe injected into an expandable container 20 (FIG. 4A) that is itselfimplanted in a targeted tissue region (FIG. 4B). As FIG. 4A shows, thecontainer is desirably pre-shaped, to assume the desired inflated shape,position, and mechanical properties.

Once suitably implanted, the container 20 is inflated by infusion of thefluid or slurry material 18, which is dispensed, e.g., from a syringe 22or the like (see FIG. 4C). In one arrangement, the injected liquid orslurry material 18 may be formulated to set in situ within the container20 (see FIG. 4D), the container and its contents serve as an implantedstatic implant 12, possessing the shape, position and mechanicalproperties to impart the desired new morphology and/or motility and/orshape to surrounding tissue, or to otherwise achieve the desiredphysiologic response. It should be appreciated that, when an implantedcontainer 20 is used to house the injected material 18, saline or afluid or slurry that does not set or cure in situ may be used to form animplanted kinetic structure 12. Furthermore, the fluid or slurrymaterial 18 may be formulated to be injected as a gel that need not setor cure to perform its intended function.

The container 20 may comprise a bioresorbable material, such aspolyglycolic acid, a polymer used for resorbable sutures and otherdevices within the body. In this arrangement, once the container 20 isresorbed, only the in situ-setting fluid of slurry material 18 willremain to serve as the implanted kinetic structure 12.

B. Shaped Static Structures

As FIG. 5A shows, an implanted static structure 12 can be formed—e.g.,by bending, shaping, joining, machining, molding, braiding, assembly, orextrusion—from a biocompatible metallic and/or polymer and/or fabricand/or textile and/or ceramic material, or a metallic and/or polymerand/or fabric and/or textile and/or ceramic material that is suitablycoated, impregnated, or otherwise treated with a material to impartbiocompatibility, or a combination of such materials. For example,pre-shaped, static structures 12 can be formed from acetal resins(Delrin® material, Celcon® material), Teflon® material, and/or siliconerubber compounds.

Implanted static structures 12 formed from pre-shaped metallic and/orpolymeric and/or fabric and/or textile and/or ceramic materials are wellsuited for implantation in the tongue, the vallecula, or soft palate, aswell as other targeted pharyngeal structures and other anatomiccomponents within the pharyngeal conduit. FIG. 5B shows the pre-shapedstatic structure 12 implanted, for the purpose of illustration in thevallecula. Once suitably implanted in a targeted tissue region, thestatic implant 12 possesses the shape, position and mechanicalproperties to impart the desired new morphology and/or motility and/orshape to surrounding tissue, or to otherwise achieve the desiredphysiologic response.

C. Bending Structures

As FIG. 6A shows, an implanted static structure 12 can be formed by anarray of individual implants 24 sized and configured to be spaced-apartalong an arc. The radius of the arc and the spacing between theindividual implants 24 along the arc are predetermined, so thatindividual implants 24 will move successively closer together as thetissue develops the morphology and/or motility and/or shape conducive tocollapse. The radius of the arc and spacing distance are pre-selected sothat, before tissue collapse occurs (see FIG. 6B), spacing between theindividual implants 24 will diminish, compressing tissue between them.The spacing between individual implants 24 may disappear, as theimplants 24 come into contact with or abutment against each other. Whentissue compression occurs, the array of implants 24 possesses acomposite shape, position and mechanical properties to impart a desirednew morphology and/or motility and/or shape to surrounding tissue, toresist tissue collapse. Still, when collapse of the tissue is notimminent (see FIG. 6A), the implants 24 occupy a spaced-apart,non-contiguous relationship, which does not compress tissue orsignificantly affect the morphology and/or motility and/or shape tosurrounding tissue.

As FIGS. 6C and 6D show, individual, spaced-apart implants 24 within thearray may be linked together, e.g., by plastic and/or metal and/orfabric and/or textile and/or ceramic material 26, to help keep theimplants 24 in a desired spatial relationship. The mechanical propertiesof the linking material 26 also affects the mechanical properties of thearray prior to tissue compression.

As FIGS. 6E and 6F show, the implant 12 can comprise a body 28 havingone or more preformed hinge points 30. When collapse of the tissue isnot imminent (see FIG. 6E), the hinge points 30 are open, and the body28 does not significantly affect the morphology and/or motility and/orshape to surrounding tissue. However (see FIG. 6F), the hinge points 30close as the tissue develops the morphology and/or motility and/or shapeconducive to collapse. With the hinge points 30 closed, the body 28possesses the shape, position and mechanical properties to impart adesired new morphology and/or motility and/or shape to surroundingtissue, to resist tissue collapse.

When the hinge points 30 are closed, the mechanical properties of thematerial of the body 28 determine the magnitude of the resistance totissue collapse. The material of the hinged body 28 (which can compriseplastic and/or metal and/or fabric and/or textile and/or ceramic) can bestiff or flexible, or elastic or in-elastic, or combinations thereof. Ifelastic, the hinged body 28 can function, when the hinge points 30 areclosed, as a kinetic implant structure 12, as will be described below.The hinge points 30 can also be varied in terms of closure angle andspacing, to provide along the length of the hinged body 28, regions ofdiffering resistance to closure. The hinged body 28 can also be made ofmaterials having different mechanical properties, to provide along thelength of the hinged body regions of differing flexibility and/orelasticity.

III. Illustrative Implanted Kinetic Structures Useable with the ForceSystem

A. Continuously Kinetic

1. Shaped Springs

As FIG. 7A shows, an implanted kinetic structure 12 can exert a dynamicreactive force by virtue of elasticity or spring bias. The elasticity orspring bias places the kinetic structure under normal compression, whichimparts a desired shape to the structure and also provides an elasticresistance to a change in that shape.

Spring-biased kinetic structures 12 formed from pre-shaped metallicand/or polymeric and/or fabric and/or textile and/or ceramic materialsare well suited for implantation in the tongue, the vallecula, softpalate, a pharyngeal wall, as well as other targeted pharyngealstructures and other anatomic components within the pharyngeal conduit.FIG. 6B shows an illustrative spring-biased kinetic structure implanted,for purposes of illustration, in a pharyngeal wall.

The structure 12 is formed, e.g., from a shaped elastic or super-elasticplastic or metal or alloy material 32. The structure 12 includes apreformed biased toward a desired shape, which, in the illustratedembodiment is shown to be a curved configuration conducive to bracingthe tissue in the pharyngeal wall against collapse into the airway.Movement of the tissue into the airway is kinetically resisted by thespring-biased elasticity of the structure 12. The structure 12 is shownin FIGS. 7A and 7B to be a flat strip. However, the structure can bewire-formed, or tubular, or possess virtually any other cross sectionalconfiguration.

As FIGS. 7C and 7D show, individual spring-like structures 36 exertingdynamic reactive force by virtue of elasticity or spring bias can bejoined by hinge points 34. When collapse of the tissue is not imminent(see FIG. 7C), the hinge points 34 are open, and the hinged bodies 36 donot significantly affect the morphology and/or motility and/or shape tosurrounding tissue. However (see FIG. 7D), the hinge points 34 close asthe tissue develops the morphology and/or motility and/or shapeconducive to collapse. With the hinge points 34 closed, and the bodies35 collectively assume a spring-loaded condition to impart a desired newmorphology and/or motility and/or shape to surrounding tissue, to resisttissue collapse. When the hinge points 34 are closed, the collectiveelastic or spring-biased mechanical properties of the individualspring-loaded bodies 36 kinetically resist tissue collapse. Aspreviously discussed with respect to the hinged body 28 shown in FIGS.6E and 6F, the hinge points 34 can be varied in terms of closure angleand spacing, to provide along the length of the hinged body 36, regionsof differing resistance to closure. The individual spring-likestructures 36 linked by the hinges 34 can also be made of materialshaving different elastic or spring-biased properties, to provide alongthe length of the hinged body regions of differing kinetic resistance totissue collapse.

2. Shaped Magnetic Arrays

An implanted kinetic structure 12 can also exert a dynamic force byvirtue of magnetic forces. The magnetic forces impart a desired shape tothe implant 12, while also providing a magnetic field resistance to orbias against shape change. FIGS. 8A(1), (2), and (3) and 8B show anillustrative magnetically shaped array of permanent magnets 38 mountedon a flexible, inelastic carrier 40. The carrier 40 may carry one ormore rows of magnets 38.

The permanent magnets 38 on the carrier 40 are characterized as showingresistance to external demagnetizing forces once being magnetized.Examples of known permanent magnet materials include alloys ofNeodymium-Iron-Boron (NdFeB), alloys of Aluminum-Nickel-Cobalt (AlNiCo),and Samarium Cobalt (SmCo). These materials are typically coated withNickel. An electromagnet (current flowing through a coil of wire) can besubstituted for a permanent magnet.

The permanent magnets 38 on the carrier 40 each generate an externalmagnetic field. As FIG. 8A(1) shows in diagrammatically, the permanentmagnets 38 are arranged on the carrier 40 with like magnetic polesfacing each other (North-North or South-South). According to physicallaws, poles of like polarity repel each other with a magnetic force. Theforce of magnetic repulsion depends on the strength of the magnets andthe distance between the poles. The permanent magnets 38 on the carrier40 can also be arranged with the same poles facing the carrier 40, asshown in FIGS. 8A(2) and 8A(3). According to magnetic force calculationsand finite element analysis, permanent magnets 38 like that shown inFIG. 8A(1), (2), or (3)—having the same poles facing the samedirection—will repel each other if they are arranged in close proximity.

As FIG. 8B shows, the magnetic repulsion between neighboring magnets 38bends the flexible carrier 40. Furthermore, the repelling force betweenneighboring magnets 38 gets stronger as distance between the polesdecreases, and it is this continuous, dynamic force that resistsstraightening of the carrier 40 out of its magnetically set shape. Thisdynamic, magnetically induced resistance to shape change, in turn,exerts a dynamic force on neighboring tissue, to impart a desired newmorphology and/or motility and/or shape to the tissue, together with acorresponding resistance to change in this condition, to achieve thedesired physiologic response.

The carrier 40 is desirably made from a material that impartsbiocompatibility, durability, and flexibility to the magnetic array. Thecarrier 40 may be made, e.g., of a flexible or semi-rigid material suchas polycarbonate, silicone rubber, polyurethane, etc, or a flexible orsemi-rigid plastic and/or metal and/or fabric and/or textile and/orceramic material. The material of the carrier 40 can enclose the magnets38, or the magnets 38 can be carried on the surface of the carrier 40.The spacing between the magnets 38 on or within the carrier 40 providesthe requisite flexibility desired. The individual magnets 38 can havevarious geometries—rectangular, cylindrical, spherical, oval, etc.—aslong as the desired physiologic response is achieved.

Flexible magnetically shaped structures 12 are well suited forimplantation in targeted pharyngeal structures and other anatomiccomponents within the pharyngeal conduit, e.g., the tongue, vallecula,soft palate/uvula, and a pharyngeal wall. FIG. 8C shows magneticallyshaped structures 12 implanted, for the purpose of illustration, inpharyngeal walls. A magnetically shaped structure 12 can implantedalone, e.g., in a pharyngeal wall, or in conjunction with othermagnetically shaped structures, as FIG. 8C shows.

As FIG. 8D shows, one or more magnetically shaped structures 12 in thepharyngeal wall can be juxtaposed to one or more permanent magnetstructures 42 implanted in the posterior of the tongue. The magnets inthe structures 12 and the magnet structures 42 in the tongue possess thesame magnetic orientation. The repelling force between the opposingtongue magnet(s) and pharyngeal wall structures shape the pharyngealwall structures in the manner described above. This juxtaposition ofmagnets resists collapse of the airway as the tissue relaxes and comesinto proximity, particularly during Phase IV of the respiratory cycle.Other arrangements are possible, as will be described in greater detaillater.

B. Selectively Kinetic

1. Shape Memory Structures

An implanted kinetic structure 12 (see FIG. 9A) can exert a dynamicforce by virtue of a selectively activated shape memory. In thisarrangement, the implanted kinetic structure 12 is made from a class ofmaterials 44 that have the ability to return to remembered shapes whenactivated by an external stimulus (see FIG. 9B). The structures 12 canbe made from, e.g., shape memory alloys, shape memory polymers, orferromagnetic shape memory alloys. Illustrative embodiments follow.

a. Shape Memory Materials

An implanted kinetic structure 12 can comprise a shape memory metalmaterial 44 that assumes a predetermined, remembered shape in responseto an applied activation energy 46 (see FIG. 9B). The activation energy46 can comprise, e.g., electrical energy, mechanical energy, thermalenergy, electromagnetic energy, acoustic energy, or light energy.

The shape memory material 44 can comprise an alloy, e.g., Nitinol® alloy(an alloy consisting of nickel and titanium), and copper based alloys,most commonly Cu—Zn—Al and Cu—Al—Ni. The shape memory material 44 canalso comprise a shape memory polymer.

FIG. 10A shows an implanted kinetic structure 12 made, e.g., of aNitinol® shape memory alloy. Shape memory kinetic structures 12 are wellsuited for implantation in the tongue, the vallecula, or the softpalate, as well as other targeted pharyngeal structures and otheranatomic components within the pharyngeal conduit. In FIG. 10A, thestructure 12 is implanted, for the purposes of illustration, in thepharyngeal wall. As shown in FIG. 10A, the structure 12 possessesrelatively compliant mechanical properties at certain temperatureconditions, which is sometimes called the soft martensitic phase. Inresponse to increased temperature conditions, the structure 12 assumesless compliant mechanical properties (see FIG. 10B), accompanied byaccelerated shape change. This is sometimes called the hard austeniticphase. In this phase (as shown in FIG. 10B), the structure 12 provides adynamic resistance to shape change. In the illustrated embodiment, thechange in temperature conditions is brought about by an externalactivation energy source 46 that is used when activation is desired. Theactivation energy source 46 can be worn by the individual (see FIGS. 10Band 10C), e.g., carried by a collar 48 secured about the neck of theindividual. The activation source 46 (see FIG. 10D) can also be carriedon a wand 50 that is placed in the oral cavity when activation isdesired. The activation source 46 can comprise a source of heat.Alternatively, the activation source 46 can comprise an electrical fieldsource to resistively heat the structure, or a mechanical energy source.Alternatively, magnetic alloys could be used that heat up when exposedto an external alternating magnetic field. As FIG. 10A shows, therelatively compliant mechanical properties of the structure return whenthe structure 12 is cooled sufficiently to return to the softmartensitic phase. For example, the individual could drink asufficiently cool or cold liquid, or use the wand 50 set at asufficiently cool temperature to return the structure to a relativelycompliant condition.

b. Shape Memory Ferromagnetic Alloys

An implanted kinetic structure 12 can comprise a shape memoryferromagnetic alloy 52 that assumes a predetermined, remembered shape inresponse to a magnetic field 54. The alloy 52 can comprise, e.g.,Ni—Mn—Ga alloys close to the stoichiometric composition Ni₂MnGa.

Shape memory ferromagnetic kinetic structures 12 are well suited forimplantation in the tongue, the vallecula, the soft palate, or apharyngeal wall, as well as other targeted pharyngeal structures andother anatomic components within the pharyngeal conduit. FIG. 11A showsan implanted kinetic structure 12 made of a shape memory ferromagneticmemory alloy 52 implanted, for the purposes of illustration, in the baseof the tongue. As FIG. 11A shows, the structure 12 possesses relativelycompliant mechanical properties in the absence of an external magneticfield 54. In response to exposure to an external magnetic field 54 (seeFIG. 11B), the structure 12 assumes less compliant mechanicalproperties, accompanied by pronounced shape change. In this phase, thestructure 12 provides a stiffening resistance to shape change. In theillustrated embodiment, the external magnetic field 54 is brought aboutpermanent magnets or an electro-magnet worn by the individual, e.g.,carried by a collar 48 secured about the neck of the individual, in themanner shown in FIG. 10C. The source of the magnetic field 54 can alsobe carried on a wand 50 in the manner shown in FIG. 10D. In the absenceof the external magnetic field 54 (as FIG. 11A shows), the relativelycompliant mechanical properties of the structure 12 return.

2. Selective Magnetic Activation

As FIGS. 12A and 12B show, an implanted kinetic structure 12 cancomprise an array of soft ferromagnetic materials 58 mounted on aflexible carrier 56. A soft ferromagnetic material 58 is a material thatcan be demagnetized very easily, once having been magnetized. In otherwords, a soft ferromagnetic material 58 retains almost no residualmagnetism after the magnetizing force is removed. Soft ferromagneticmaterials 58 have very high permeability and saturation magnetization,but very low intrinsic coercivity. Soft magnetic materials 58 can beattracted by a permanent magnet or an electromagnet.

Examples of known soft ferromagnetic materials 58 include Iron (Fe);Nickel (Ni); Permendur; MuMetal, low-carbon steels, Iron-Cobalt alloys(Fe—Co); silicon steels; and amorphous alloys.

The soft ferromagnetic materials 58 can be machined, laser cut,chemically etched, or EDM manufactured into magnetic blocks and encased,packaged, or otherwise arranged on the flexible carrier 56 to form amagnetic array structure 12, as FIGS. 12A and 12B show. In the absenceof a magnetic force 60, the array structure 12 possesses compliantmechanical properties.

In this arrangement (see FIG. 12C), when activation of the softferromagnetic array structure 12 is desired, an external source ofmagnetic force 60 (which can comprise, e.g., a second array withpermanent magnets, or a single permanent magnet, or an electromagnet)can be donned by the individual (e.g., in the collar 48 shown in FIG.10C or wand 50 shown in FIG. 10D). Exposure of the soft ferromagneticarray structure 12 to the source of magnetism 60 causes the array tobecome magnetic. The external magnetic force 60 is sized and configuredto make adjacent surfaces of soft magnetic blocks 58 have unlike poles,and are thereby attracted to one another. This attraction will case thecarrier 56 to bend (as FIG. 12C shows), until the magnetic blocks 58come into contact with each other. This attraction and contact will bemaintained until the source of magnetism 60 is removed or reduced inintensity. This continuous, dynamic magnetic force will resistsstraightening of the carrier 56. This dynamic, magnetically inducedresistance to shape change, in turn, exerts a dynamic force onneighboring tissue, to impart a desired new morphology and/or motilityand/or shape to the tissue, together with a corresponding resistance tochange in this condition, to achieve the desired physiologic response.Selectively magnetically shaped structures 12 are well suited forimplantation in the tongue, vallecula, soft palate, a pharyngeal wall,as well as in other targeted pharyngeal structures and other anatomiccomponents within the pharyngeal conduit. FIG. 12E shows a magneticallyshaped structure 12 of the type shown in FIGS. 12A and 12B implanted,for the purpose of illustration, in the soft palate. Exposure of thestructure 12 to a source of magnetism 60 bends the structure 12 in themanner shown in FIG. 12C, pulling the soft palate forward.

As FIG. 12D shows, the soft ferromagnetic material 58 can be mounted tothe carrier 56 to cause serpentine bending. Serpentine bending can beachieved by affixing similar ferrous blocks 58 on the opposite surfaceof the flexible carrier 56, displaced axially from the blocks on thefirst surface. The flexible carrier 58 may be produced with an offsetbetween the two areas if it is desirable to maintain a thin overallthickness of the assembly.

IV. Biocompatibility

As FIG. 13 shows, a given implanted static or kinetic structure 12 ofwhatever form or configuration can be coated, plated, encapsulated, ordeposited with a selected protective material 62. The protectivematerial 62 is selected to provide a corrosion resistant andbiocompatible interface, to prevent interaction between the structureand tissues/fluids of the body. The protective material 62 is alsodesirably selected to form a durable tissue interface, to providelongevity to the structure, and thereby provide resistance to structuralfatigue and/or failure. The protective material 62 can be selected amongvarious types of materials known to provide the desiredbiocompatibility, resistance to corrosion, and durability. For example,the protective material 62 can comprise gold and/or titanium materialplated, deposited, or otherwise coated upon the structure. As anotherexample, the protective material 62 can comprise a parylene coating. Asother examples, the protective material 62 can comprise a siliconepolymer, a non-toxic epoxy, a medical grade polyurethane, or a U.V.curable medical acrylic co-polymer.

The protective material 62 may also incorporate anticoagulants and/orantibiotics.

V. Fixation of Static or Kinetic Implants

A. Use of Mechanical Fixation Materials

The position of implanted structures 12 can be fixed against migrationin a targeted tissue region within the pharyngeal conduit usingconventional mechanical fixation materials and techniques known in thesurgical arts, e.g., non-resorbable sutures, screws, staples, adhesives,or cements such as polymethyl methacrylate (PMMA) cement. For example,the structures 12 can include preformed apertures 64 to accommodate thefixation material, i.e., sutures, screws or staples. Fixation to tissueenhances the fixation or bracing function of the implanted static orkinetic structure.

The tissue to which a given implant is fixed can include soft tissue inthe pharyngeal walls, the base of the tongue; the vallecula; the softpalate with uvula; the palatine tonsils with associated pillar tissue,and the epiglottis.

The tissue can also include bone within the pharyngeal conduit, e.g., ahyoid bone or a vertebra, as will be next described.

B. Fixation to a Vertebra

In some cases, implantation of one or more structures 12, with fixationto bone, may be desirable. As FIG. 14A shows, one or more givenimplanted static or kinetic structures 12 may be fixed to one or morevertebrae with fixation elements 66 such as bone screws and/or adhesivesand/or bone cements. As FIG. 20A also shows, such structures 12 can befixed, e.g., at or near the pedicles. Alternatively (as FIG. 14B shows),one or more implanted static or kinetic structures 12 may be fixed witha fixation element 66 such as a bone screw to other regions of thevertebra. A single fixation point may be used to secure multipleimplanted static or kinetic structures.

With vertebra fixation, several static or kinetic structures 12 may beoriented horizontally in a single row or in a fan or in a verticallystacked relationship along the pharyngeal conduit (as shown in FIG.20B), in an angular path within a lateral pharyngeal wall (as shown inFIG. 20A).

In this way, fixation or bracing of the lateral pharyngeal wall can beachieved by using implanted static or kinetic structure or structures 12that are stabilized with a vertebral column bone anchor. Fastening tobone enhances the fixation or bracing function of the implanted staticor kinetic structure 12.

In representative procedure for implanting a pharyngeal wall implant 12or other pharyngeal wall device that is fixed to a vertebral body (seeFIGS. 24A to 24C): (1) a patient is positioned in the Rose tonsillectomyposition (supine, head extended), and with the pharynx exposed using aCrowe Davis, or similar tonsillectomy mouth retractor; (2) the anterioraspect of the cervical vertebra is identified along the posteriorpharyngeal wall; (3) a small transverse incision (see FIG. 24A) is madejust lateral to midline, and deepened to the body of a cervicalvertebra, exposing bone; (4) the implant 12 can be inserted through thisincision (as FIG. 24A shows) and tunneled submucosally along the lateralpharyngeal wall, using manual palpation along the mucosa for guidance;(5) when proper placement is established, the implant 12 is released;(6) a new implant 12 (see FIG. 24B) is then loaded through the samesmall incision, angling the placement downward. In this fashion, anarray of implants 12 can be placed within the submucosal space along thepharyngeal wall. The proximal ends of all the implants 12 placed areconfigured with a rounded ring (like a flat washer). All of these ringsare then placed on the shaft of a self tapping screw (see FIG. 24C)which is then secured to the vertebral column as the bone anchor. Thearea is irrigated with antibacterial solution and the small incision isclosed in two layers (periosteum, then mucosa). An identical procedureis then carried out on the contralateral pharyngeal side, establishingtwo separate sets of arrayed submucosal wall implants.

C. Tissue in-Growth Surfaces

In addition to any of the just-described tissue fixation methodologies,the implanted static or kinetic structure can include a tissue in-growthsurface 68 (see FIG. 15). The surface 68 provides an environment thatencourages the in-growth of neighboring tissue on the implantedstructure. Tissue in-growth is defined as the filing of pores in animplanted material with cellular material. As in-growth occurs, theimplanted structure 12 will become securely anchored, resistingmigration or extrusion from the tissue. The tissue in-growth surface 68thus enhances tissue adhesion and stabilization, and thereby furtherstabilizes and fixes the position of the implanted structure 12 in thetargeted implantation site.

The tissue in-growth surface 68 can be formed in various ways. Forexample, the surface can comprise an open cellular or fibrous structure,biologically inert in nature and known to support in-growth by bodytissue. One material that exhibits this characteristic is expanded PTFE(polytetrafluoroethylene or Teflon®—DuPont). This material may beprepared by radiation bombardment to cause the structure of the materialto become fractured and fibrous in nature. The resulting material isopen and porous, providing fissures into which fluids may enter and towhich body tissue can attach and grow. Other such inert polymers andeven metals (such as nickel titanium—Nitinol®) when treated or coated toprovide a granular or fibrous surface, may offer a substrate for tissuein-growth. An alternative form of the in-growth matrix may be an opencelled polymeric foam (e.g., PVA foam) in place of a material that mustbe irradiated to attain the open fibrous or granular nature.

The in-growth surface 68 can also comprise, e.g., woven or knittedDacron® (PET) fabric placed on a substrate of polydimethylsiloxane(PDMS) or polyurethane (PU); metallic surface structures created byelectroform processing; a sintered metal surface (e.g., stainless steel,platinum, iridium, or alloys thereof); parylene coatings; or diffusionlimited aggregated silicones. The in-growth surface can also comprisemechanical structures, such as spike, staples, times, coils, orperforations of appropriate dimensions associated with the implant. Theimplant may also include compounds to promote coagulation and/orantibiotics to prevent infection, used alone or in combination with thein-growth surface 68.

It may be desirable to mechanically anchor the implant 12 while allowingin-growth to occur. Temporary anchoring may be accomplished by use ofresorbable sutures, screws or other mechanical fasteners made ofresorbable materials such as polyglycolic acid or other similarcompounds. Tissue adhesives and/or tissue cements such as PMMA may alsobe used to provide tissue adhesion, fixation, and stabilization.

Complete tissue in-growth is determined by the percentage of thematerial that has been infiltrated by the cellular material. With poresizes from 100 micrometers to 500 micrometers, blood vessels can beformed. With pore sizes of 10 micrometers to 100 micrometers, cells tosmall capillaries can form.

VI. Orienting Implanted Static or Kinetic Structures

The orientation of the static or kinetic structures can vary accordingto the particular anatomy of the targeted tissue region and itsenvirons.

A. Horizontal Orientation

For example, the particular anatomy and tissue mass of the targetedtissue region may lend itself to the implantation of the static orkinetic structures 12 in a generally horizontal plane. With respect toanatomic landmarks, horizontal arrays extend either laterally (from sideto side) or anterior-to-posterior (front to back), following the naturalmorphology of the tissue.

For example (see FIG. 16A), the anatomy and the tissue mass of thetongue accommodates implantation of a horizontal array of static orkinetic structures 12, either laterally in the base of the tongue, oranterior-to-posterior along one or both sides of the tongue, or both. AsFIG. 16B shows, horizontal arrays of static or kinetic structures 12 canbe implanted in stacked or staggered fashion on the posterior of thetongue, at different elevations along the pharyngeal conduit.

As another example (see FIG. 17A), the anatomy and the tissue mass ofthe lateral pharyngeal wall accommodates implantation of a horizontalarray of multiple static or kinetic structures 12 following themorphology of the posterior and lateral pharyngeal walls. In thepharyngeal wall (see FIG. 17B), one or more shaped static or kineticstructures 12 can remodel tissue along a substantial portion of theairway, from the spinal column to the base of the tongue.

As FIG. 17C shows, horizontal arrays of multiple static or kineticstructures 12 can be implanted in stacked or staggered fashion withinthe lateral pharyngeal wall. The structures may be discontinuous or formconcentric bands about the pharyngeal wall at different elevations alongthe pharyngeal conduit.

B. Vertical Orientation

The particular anatomy and tissue mass of the targeted tissue region maylend itself to the implantation of multiple static or kinetic structures12 in a generally vertical plane. With respect to anatomic landmarks,vertical arrays extend in a superior (cephalad)-to-inferior (caudal)direction, following the natural morphology of the tissue mass.

For example (see FIG. 18A), the anatomy and the tissue mass of thepharyngeal wall accommodates implantation of a vertical array ofmultiple static or kinetic structures 12 following the morphology ofopposite lateral pharyngeal walls.

As FIG. 18B shows, vertical arrays of multiple static or kineticstructures 12 can be implanted either end-to-end or side-by side withinthe lateral pharyngeal wall.

As FIG. 18C shows, the anatomy and the tissue mass of the base of thetongue and the vallecula accommodate implantation of a vertical array ofmultiple static or kinetic structures 12 following the morphology ofthese anatomic components within the pharyngeal conduit.

C. Other Orientations

The particular anatomy and tissue mass of the targeted tissue region maylend itself to the implantation of multiple static or kinetic structures12 in both a generally horizontal plane and a generally vertical plane.

For example (see FIG. 19A), the anatomy and the tissue mass of thepharyngeal wall accommodates implantation of vertical arrays of multiplestatic or kinetic structures 12 with horizontal arrays of static orkinetic structures 12 along the elevation of the pharyngeal conduit.This implantation pattern makes possible the formation of dynamicbracing or fixation forces that facilitate the physiologic objective ofresisting tissue collapse along the pharyngeal conduit.

The particular anatomy and tissue mass of the targeted tissue region maylend itself to the implantation of multiple static or kinetic structures12 in angular planes (i.e., not horizontal or not vertical planes).

For example (see FIG. 19B), the anatomy and the tissue mass of thepharyngeal wall accommodates implantation of angular, non-horizontal andnon-vertical arrays of multiple static or kinetic structures 12. Thiscomplex implantation pattern makes possible the formation of dynamicbracing or fixation forces that facilitate the physiologic objective ofresisting tissue collapse along the pharyngeal conduit.

VII. Illustrative Implanted Force Systems

Based upon the foregoing discussions, a practitioner can select andassemble static and/or kinetic structures 12 in various ways to createsystems 10 of different configurations to achieve the desiredphysiologic response. The static and/or kinetic structures 12 are wellsuited for implantation within the pharyngeal walls (with or withoutfixation to a vertebral body); the base of the tongue; the vallecula;and the soft palate/uvula. Representative examples of embodiments ofmagnetic force systems 10 in certain targeted pharyngeal structures andindividual anatomic components within the pharyngeal conduit will bedescribed in greater detail now.

A. Implants within the Pharyngeal Wall and Adjacent Structures

FIG. 21 shows an illustrative embodiment of a system 10 that includesstatic and/or kinetic structures 12 that are implanted in a verticalarrays on opposite lateral sides of the pharyngeal wall (with or withoutfixation to a vertebral body), the base of the tongue, the vallecula,and the soft palate/uvula. The structures 12 can be selected among thevarious static and kinetic types previously discussed. It should beappreciated that stacked horizontal arrays, or a combination ofhorizontal and vertical arrays, or angular arrays could be used. Eachstructure remodels tissue in its vicinity, providing bracing or fixationforces that facilitate the physiologic objective of resisting tissuecollapse along the pharyngeal conduit, when imminent. It should beappreciated that static and/or kinetic structures 12 need not beimplanted precisely in the manner shown or at every anatomic site shownto achieve the desired physiologic objective.

B. Implants within the Tongue and Adjacent Structures

FIG. 22A shows another illustrative embodiment of a system 10 thatincludes static and/or kinetic structures 12 that are implanted onopposite lateral sides in the base of tongue as well as in the softpalate. The structures 12 can be selected among the various static andkinetic types previously discussed. It should be appreciated that otherarrays, or a combination of arrays arrays could be used. Each structure12 remodels tissue in its vicinity, providing bracing or fixation forcesthat facilitate the physiologic objective of resisting tissue collapsealong the pharyngeal conduit. It should be appreciated that staticand/or kinetic structures 12 need not be implanted precisely in themanner shown or at every anatomic site shown to achieve the desiredphysiologic objective.

FIGS. 22B and 22C show another illustrative embodiment of a system 10that includes one or more selectively kinetic structures 12 that areimplanted across the base of the tongue. In FIG. 22B, the implantedstructure 12 is shown in a non-activated configuration. In FIG. 22C, theselectively kinetic structure 12 is subject to a suitable activationforce (as previously described), causing the implanted structure toassume a desired activated configuration. In this configuration, theimplanted structure remodels the base of the tongue. The configurationshown in FIG. 22C includes a depression in the middle of the tonguebase, which resists closure of the airway during sleep, and a prominence72 on the right and left lateral sides of the tongue base, which serveto press against the lateral oropharyngeal tissue, holding the tongue inan anterior position.

FIGS. 22D and 22E show another illustrative embodiment of a system 10that includes one or more selectively kinetic structures 12 that areimplanted in the posterior of the tongue and vallecula. In FIG. 22D, theimplanted structures 12 are shown in a non-activated configuration,extending horizontally along the posterior of the tongue and thevallecula. In FIG. 22E, the selectively kinetic structures 12 aresubject to a suitable activation force (as previously described),causing the implanted structures to assume a desired activatedconfiguration. In this configuration shown in FIG. 22E, the implantedstructures remodel the posterior of the tongue and vallecula, creating adepression 70 that runs vertically down the posterior surface of thetongue and the vallecula.

VIII. Illustrative Structures Useable with the Pressure Chamber System

FIGS. 23A and 23B show an illustrative embodiment of a pressure chambersystem 14. The system 14 includes a collar 74 that is sized andconfigured to be removably worn about the neck of an individual when thedesired physiologic effect is desired, e.g., during sleep (as FIG. 23Ashows).

The collar 74 carries a pressure-retaining chamber 16. When the collar74 is worn, the chamber 16 encircles all or a portion of the pharyngealconduit (see FIG. 23B). The chamber 16 may comprise an elastic materialfor comfort.

An air pump 76 has an inlet that communicates with the chamber 16 and anoutlet that communicates with the ambient environment. The air pump 76can be carried by the collar 74 (as shown), or it can be located remotefrom the collar, e.g., bedside, and coupled by tubing to the air chamber16. The air pump 76 can comprise, e.g., a diaphragm pumping mechanism,or a reciprocating piston mechanism, or a centrifugal (turbine)air-moving mechanism.

The air pump 76 may be manually operated, or a power source 78 may drivethe air pump 76. The power source 78 can be, e.g., an electric motorthat can be plugged into a conventional electrical receptacle, or bebattery-powered, or both (in which case the battery can berechargeable). When driven, the air pump 76 draws air from the chamber16, to establish within the chamber 16 a pressure condition that is lessthan atmospheric.

A regulator 80 may be coupled to govern operation of the air pump 76 toestablish and maintain a desired subatmospheric pressure conditionwithin the chamber 16. The desired pressure condition is selected to beless than atmospheric pressure and is desirably less the minimumpressure condition expected experienced in the pharyngeal conduit, whichis typically encountered during the inhalation phase of the respirationcycle. The pressure selected desirably nullifies the vector sum of theextralumenal forces, which are created by the interaction of atmosphericpressure, gravity, the contractive forces within the tissue due to upperairway muscle activity, and the inward forces generated bysubatmospheric luminal pressure generated during inhalation. It isbelieved that the pressure condition established within the chamber 16should be at least −1 cm H₂O and desirable at least −10 cm H₂O. Thepressure created by the system 14 desirably also takes into accountdifferent anatomical structural differences of individual airways.

The system 14 can also include some form of physiologic feedback controlfor the air pump. In this arrangement, the system includes a monitor orsensor 82 to sense fluctuations of pharyngeal pressure during therespiration cycle. When the pharyngeal pressure meets or exceeds aselected threshold minimum pressure, the monitor 82 sends a controlsignal to the pump 76, to activate the pump 76. The pump 76, whenactivated, operates to maintain a desired pressure condition within thechamber 16 while sensed pharyngeal pressure is below the threshold. Thepump 76, when activated, could also operate to maintain a desiredpressured differential between pressure in the chamber 16 and the sensedpharyngeal pressure while sensed pharyngeal pressure is below thethreshold. Once pharyngeal pressure exceeds the threshold, the monitor82 sends a control signal to deactivate the pump 76. In this way, thesystem 14 conditions tissue to resist collapse when respiratoryconditions are most conducive to collapse, but otherwise does not affectthe tissue morphology and/or motility and/or shape. The pressure chamber16 can also serve to reduce tissue vibration and be used in thetreatment of snoring.

Other forms of physiologic feedback control can be used. For example,airflow can be measured during the respiratory cycle, and/or theexpansion/contraction of the chest can be monitored during the cycle.Chamber pressure can be varied to response to requirements dictated bythe respiratory cycle.

The above-described embodiments of this invention are merely descriptiveof its principles and are not to be limited. The scope of this inventioninstead shall be determined from the scope of the following claims,including their equivalents.

What is claimed is:
 1. An arrangement adapted to resist collapse of aportion of a pharyngeal wall, the arrangement comprising: a plurality ofindividual implants, each of the implants being sized and configured forimplantation in the portion of the pharyngeal wall and once implanted,are sized and configured to be movable among: a first arrangement inwhich the plurality of individual implants are spaced a predetermineddistance apart along an arc defined by a radius, and a secondarrangement in which one or both of the distance or radius hasdecreased.
 2. The arrangement of claim 1 wherein when disposed in thesecond arrangement, one or more of the individual implants are disposedin direct contact with another one or more of the individual implants.3. The arrangement of claim 1 wherein each of the individual implantsare linked together by a material.
 4. The arrangement of claim 3 whereinthe material comprises one or more selected from the group consistingof: a plastic, a metal, a fabric, a textile, and a ceramic.
 5. Thearrangement of claim 3 wherein the material is of a negligiblestiffness.
 6. The arrangement of claim 3 wherein the material is of astiffness sufficient to impart a flexural resistance upon adjacentimplants linked thereby.
 7. An implant sized and configured forimplantation in a portion of a pharyngeal wall and adapted to resistcollapse of the portion of the pharyngeal wall, the implant comprising:a body comprising a plurality of segments, each segment being coupled toan adjacent segment via a hinge point, wherein the body is flexible fromamong: a first arrangement in which each of the hinge points aredisposed on an open position, and a second arrangement in which one ormore of the hinge points are disposed in a closed position such that theone or more hinge points disposed in the closed position resist furtherflex of the body such hinge points.
 8. The implant of claim 7 whereinthe body comprises one or more of a plastic, metal, fabric, or ceramicmaterial.
 9. The implant of claim 7 wherein each hinge point is adaptedto delimit a spacing and a closure angle of the segments connectedthereby.
 10. The implant of claim 9 wherein the spacing delimited by onehinge point differs from the spacing delimited by another hinge point.11. The implant of claim 7 wherein closure angle delimited by one hingepoint differs from the closure angle delimited by another hinge point.12. The implant of claim 7 wherein each of the segments is formed from agenerally inelastic material.
 13. The implant of claim 7 wherein each ofthe segments is formed as a spring-like structure.
 14. A method ofbracing a portion of a pharyngeal wall, the method comprising:surgically implanting a plurality of individual implants atpredetermined spacings along an arc-shaped arrangement in the pharyngealwall.
 15. A method of bracing a portion of a pharyngeal wall, the methodcomprising implanting the implant of claim 7 in a portion of apharyngeal wall.